Telephone system.



K. S. JOHNSON.

TELEPHONE SYSTEM.

APPLICATION FILED MAY 10. 1915.

'1 162,069, Patented Nov. 30, 1915 Qm M Ken/7e? 3 Jab/760.

UNITED STATES PATENT OFFICE.

Krmmirn SIMONDS JOHNSON, or JERSEY-CITY, NEwJERsEY, ASSIGNOR 17o WESTERN ELECTRIC COMPANY, or NEW YORK. N.

Y., A CORBOR-ATION OF ILIJINOIS;

TELEPHONE Specification of Letters Patent.

Patented Nov..30, 1915.

Application filed May 10, 1915. S eria1 No. 27,020.

ertain new and useful Improvements in Telephone Systems, of whichthe following isa full, clear, concise, and exact descrip.

tion. 4

This invention relates to telephone systems, and more. particularly to substation circuits for'suchsysteins. I

"lhe object of this invention is to provide an improved and eflicient telephone substation circuit by so combining certain of the necessary devices of a substation switching set that one or more maybe made to serve a double purpose in the circuit, thereby eliminating certain devices which have here tofore been necessary.

In accordance with this invention, a substation circuit is provided with an electro magnetic signal receivingdevice, the usual transmitter and receiver, and switching means for inductively associating the re- I ceiver and the transmitter with a line circuit through the agency of the electromagnet of the signal receiving device. 1 a

For a more complete understandingof this invention, reference is made to the ac-v companying drawings showing one embodiment thereof and wherein? s Figure 1 is a diagram of a substation-circuit with the apparatus therein in its normal position; that is, with the signal receiving deviceconnected to receive signalsrand Fig. 2 is a diagram of the substation circuit when tion.

Referring to the drawings, 5 designates. an electromagnetic signal receivingdevice having a 'U-shaped core 1. Windings 6, 7, 8 and 9 of the signal 'receiving device 5 are normally connected in series with line'wires 10 and 11, through condenser 12 and switchhook contact 13.1 A transmitter 20 is ina normally open bridge of the line circuit, one, terminal being connected to an intermediate point 21 of the windings of the elec- -nal being connected to a normally open switchhook contact 13. Switchhook 24 when tromagnetic device 5, and the other termiswitchhook contact 22.- ,A- receiver '23 is normally short-circuited by means of the the substation circuit b or depressed therefore that by utilizing the apparatus is connected in talking condireleased by removing the receiver 23 the're-- from, opens the short circuit from aboutthe receiver 23 and serves to inductively connect the .transmitter 20 and the receiver 23 withthe line Wires 10 and 11 through the windings 6, 7 and 8, '9 of the electromagnetic this condition of cing shown in Fig. 2. When the switchhook 24 is in its normal position as shown in Fig. 1, the circuit for signaling current (the source of which is'not shown) is from line wire 10, windings 6, 7, 8 and 9'in series, condenser 12 and switchhook contact 13.;to line wire 11. When the switchhook 24. rises, upon the removal of the receiver 23, the open bridge signal receiving device 5,

including the transmitter20 is closed at switchhook contact 22, and the electromagnet of the signal receiving device 5, through its windings 6, 7 and 8, 9, acts as an induction coil serving to inductively associate the transmitter and receiver with the line wires.

Whenthe receiver is ofl' the switchhook,

windings 6 and 7 are in series and form one winding of an induction coil, while windings 8 and 9 are in series formingthe otherwinding of the induction coil.

. Heretofore in telephone s'ubstation circuits employing induction coils,'thes e induction coils have been separate and distinct from It will be seenthe signal receiving device.

the present 1nvent-ion,- an efficient telephone substation cir-,

cuit is obtained, and the cost of such circuits is materially reduced by the elimination of the separate induction coils.

. What is claimed is:

-1. In a telephone substation circuit, in"

combination, a line circuit, 'an= electromagnetic device normally in circuit with said line't'o receive signals, a transmitter and a. receiver, and switching means for including said transmitter and said receiverin induc-y magnet of said device.

2. In a telephone substation circuit, in combination, a line circuit, an electromagnetic device normally in circuit'with'said line to' receive signals, a plurality of windings for said device, a transmitter in a normally open bridge of said-line circuitlafid having one terminal connectedfto' an inter mediate point of said windings, a 'ireceivei', and switchingmeans for closings tive-relation to said line through -the electroaid bridge and for including said receiver in transformer'rclation to said line circuit through saidwindings. V v

3. In a telephone substation circuit, in combination, a line circuit, an electromagnetic deviceinormally in circuit with said 'line to receive signals, a plurality of windings for said device, artransmitter and a relceiver, and switching means for including netic device normally in circuit with said line to receive signals, a U shaped core therefor, a plurality of windings on each leg'of said core, a transmitter and a receiver, switching means and circuit connections whereby upon the actuation of said switching means one winding of each leg forms a winding of an induction coil and another winding of each leg forms another winding thereof through which said transmitter and said receiver are connected to said line.

In witness whereof I hereunto subscribe my name this 8th day of May, D. 1915.

KENNETH SIMONDS J UHNSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of .Patents,

' Washington, D. 0." 

